Function linker_load_module

freebsd/kern/kern_linker.c:2086–2152

* Find a file which contains given module and load it, if "parent" is not * NULL, register a reference to it. */

 * NULL, register a reference to it.
 */
static int
linker_load_module(const char *kldname, const char *modname,
    struct linker_file *parent, const struct mod_depend *verinfo,
    struct linker_file **lfpp)
{
	linker_file_t lfdep;
	const char *filename;
	char *pathname;
	int error;

	sx_assert(&kld_sx, SA_XLOCKED);
	if (modname == NULL) {
		/*
 		 * We have to load KLD
 		 */
		KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
		    " is not NULL"));
		if (!linker_root_mounted())
			return (ENXIO);
		pathname = linker_search_kld(kldname);
	} else {
		if (modlist_lookup2(modname, verinfo) != NULL)
			return (EEXIST);
		if (!linker_root_mounted())
			return (ENXIO);
		if (kldname != NULL)
			pathname = strdup(kldname, M_LINKER);
		else
			/*
			 * Need to find a KLD with required module
			 */
			pathname = linker_search_module(modname,
			    strlen(modname), verinfo);
	}
	if (pathname == NULL)
		return (ENOENT);

	/*
	 * Can't load more than one file with the same basename XXX:
	 * Actually it should be possible to have multiple KLDs with
	 * the same basename but different path because they can
	 * provide different versions of the same modules.
	 */
	filename = linker_basename(pathname);
	if (linker_find_file_by_name(filename))
		error = EEXIST;
	else do {
		error = linker_load_file(pathname, &lfdep);
		if (error)
			break;
		if (modname && verinfo &&
		    modlist_lookup2(modname, verinfo) == NULL) {
			linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
			error = ENOENT;
			break;
		}
		if (parent) {
			error = linker_file_add_dependency(parent, lfdep);